| Hemsley Morgan Limited | Real estate | 2015 |
| Henley Court Management Limited | Households | 1985 |
| Herb U.K. (Holdings) Limited | Professional & scientific | 2006 |
| Herb U.K. Limited | Wholesale & retail | 1990 |
| Here to Talk Ltd | Education | 2022 |
| Heritage Applications Limited | Professional & scientific | 2015 |
| Heritage Renovations Ltd | Other services | 2023 |
| Hertford Securities Limited | Real estate | 1994 |
| HG & G Ltd | Health & social care | 2021 |
| HG Plant Services Ltd | Construction | 2016 |
| Hi-Nets International Limited | Manufacturing | 2024 |
| High Marryats Limited | Households | 1964 |
| Highfield BED and Breakfast Limited | Manufacturing | 2016 |
| Highfield House (Lymington) Limited | Households | 1995 |
| Hill & Hill Holdings Ltd | Real estate | 2026 |
| Hill House Highfield Ltd | Households | 2006 |
| Historic Metal Works Limited | Wholesale & retail | 2010 |
| Hive of Beauty Limited | Wholesale & retail | 2015 |
| Holland's of Milford Ltd | Wholesale & retail | 2020 |
| Hollywood Lane Design Ltd | Professional & scientific | 2019 |
| Holt Investments (2022) Ltd | Hospitality | 2022 |
| Home Minders & Home Services Limited | Administrative & support | 2005 |
| Hope Aviation Limited | Agriculture & fishing | 2009 |
| Hordle Construction Limited | Other services | 2003 |
| Hordle Mews Management Limited | Households | 2006 |
| Horseshoe Homes Ltd | Extraterritorial | 2010 |
| Hot TUB Hire Limited | Administrative & support | 2019 |
| Hotlogic Limited | Information & communication | 2004 |
| House of Aquarius Limited | Construction | 2001 |
| House of Quarr Limited | Households | 2016 |
| Howard Risk Associates Ltd | Professional & scientific | 2013 |
| Howells & Co Limited | Administrative & support | 2010 |
| Howfar Innovation Ltd | Professional & scientific | 2018 |
| HS Butyl Limited | Manufacturing | 2011 |
| Huddleston Fireplaces Limited | Wholesale & retail | 2018 |
| Huffice Ltd | Professional & scientific | 2021 |
| Hughes Advisory Limited | Information & communication | 2012 |
| HUM Saath Limited | Arts & recreation | 2024 |
| Human Asset Limited | Education | 2001 |
| Human Upgrade Ltd | Education | 2025 |
| Humboldt Trading Limited | Wholesale & retail | 2007 |
| Hundred Books Limited | Administrative & support | 2024 |
| Hunters South Financial Services Limited | Financial services | 2023 |
| Hursdrex Limited | Real estate | 1959 |
| Hurst Point Owners Association Limited | Households | 2011 |
| Hurst Spit Holdings Ltd | Real estate | 2022 |
| Hurst View Leisure Ltd. | Hospitality | 2001 |
| Hurstview Homes Ltd | Construction | 2020 |
| Husky Waters Limited | Real estate | 2024 |
| Hutchwick Estates Ltd | Construction | 2022 |
| Hyett & Baxter Limited | Construction | 2013 |
| Hypro Developments Limited | Manufacturing | 1976 |
| Hythe & Waterside Lettings Limited | Real estate | 2013 |
| Hythe & Waterside Properties Limited | Real estate | 2005 |
| I P L Haulage Ltd | Transport & logistics | 2002 |
| IBR Business Solutions Limited | Professional & scientific | 1999 |
| IBS Marine Supplies Ltd | Wholesale & retail | 2024 |
| Icaro Consulting Limited | Professional & scientific | 2008 |
| Idonith Ltd | Information & communication | 2005 |
| IF7 Capital Ltd | Information & communication | 2024 |
| IG VF Engineering Limited | Professional & scientific | 2024 |
| IN the Dogs House Ltd | Professional & scientific | 2022 |
| INBOX43 Ltd | Other services | 2018 |
| Incorporate Venues Limited | Administrative & support | 2005 |
| Independence Assured Holding Company Limited | Financial services | 2017 |
| Independence Assured Limited | Other services | 2013 |
| Indigo Charlie Tango Limited | Information & communication | 2024 |
| Influence Solutions Group LLP | | 2017 |
| INNOV8 Engineering Ltd | Professional & scientific | 2023 |
| Insight Freelance Ltd | Professional & scientific | 2020 |
| Insiteworx Ltd | Information & communication | 2017 |
| Inspirance Limited | Professional & scientific | 2010 |
| Inspired Operations Ltd | Information & communication | 2018 |
| Interlogo London Limited | Manufacturing | 1980 |
| International Switch Class Limited | Arts & recreation | 2025 |
| Interspire Ltd | Information & communication | 2018 |
| Intricate Detail SO41 Ltd | Professional & scientific | 2025 |
| Inverbrook Capital Limited | Professional & scientific | 2018 |
| IO TEN Limited | Information & communication | 2016 |
| Isabel 5 LLP | | 2021 |
| Island Point Management Company Limited | Households | 1988 |
| Islander Digital Limited | Financial services | 2021 |
| Izit Design Limited | Wholesale & retail | 2010 |
| Izit Innovation Ltd | Wholesale & retail | 2018 |
| J & S Butchers Ltd | Wholesale & retail | 2014 |
| J B Elite Floor Repairs Ltd | Construction | 2010 |
| J.R.T. Associates Ltd | Information & communication | 2001 |
| Jaccss Ltd | Real estate | 2014 |
| Jacinta Residents Company Limited | Households | 2001 |
| Jack & the Wolfe Ltd | Other services | 2019 |
| Jackman Associates Limited | Extraterritorial | 1998 |
| Jacoll Investments Limited | Real estate | 2022 |
| Jake Equities UK Ltd | Real estate | 2019 |
| Jakes Independent Music Consulting Ltd | Information & communication | 2011 |
| Jakes Independent Music Ltd | Information & communication | 2012 |
| James URE & Co Ltd | Wholesale & retail | 1976 |
| James Whyte Ltd | Professional & scientific | 2017 |
| Jamesallautomotivemachineservices Ltd | Manufacturing | 2025 |
| Janette Delaney Retail Advisory Co. Ltd | Professional & scientific | 2025 |
| Japan Invested Properties Ltd | Real estate | 2024 |